The present invention relates to a filter assembly adapted to provide liquid coffee or like filterate and which is storable in a folded compact size, easy to use and economical.
While various methods are available today for preparing coffee, for example, dripping is generally accepted as comparatively simple and convenient method. For the drip type method, use is extensively made of a dripper in the form of a piece of cloth, plastics or ceramics though requiring some troublesome work for cleaning it after the use or for the storage. There have been proposed filters formed of paper sheets or plastic films which are not costly and relatively easy to handle.
One of such a type of filters is disclosed in Japanese Utility Model Publication No. 52-2703/1977. This filter comprises a support plate which is formed with an opening in its intermediate portion and foldable support pieces in its laterally opposite portions. The support pieces adjoin the rest of the support plate through fold lines, respectively. Lugs extend outward from the ends of the individual support pieces. A sack of filter paper is adhered along its peripheral edge portion to the back of the support plate to surround the opening. The support pieces are folded along the fold lines and then set upright on the upper edge of a cup or like receptacle by engaging the lugs with the receptacle. However, the filter is merely laid on the receptacle and, therefore, unstable due to the simple engagement of the lugs with the receptacle. The filter tends to fall down or have the support pieces disengaged from the edge of the receptacle when hot water is being poured into the filter due to the weight of the hot water. Thus folded into the upright position, the support legs constantly tend to restore its flat non-folded position moving outward away from each other. This brings about another problem that the support provided by the lugs is too weak to eliminate the need for cares during framing of such a filter assembly.